Fan construction of acid resistant plastic material



' W. W. PABST Jan. 3, 1961 FAN CONSTRUCTION OF ACID RESISTANT PLASTIC MATERIAL 4 Sheets-Sheet 1 Filed Nqv. 24. 1953 HF w N NR m mm INC/ENTORS Wazpnm 52 A ORNEY Jan. 3, 1961 w.w. PABST 2,967,014

FAN CONSTRUCTION OF ACID RESII ISTANT PLASTIC MATERIAL Filed Nov. 24. 1'95: 4 Sheets-Sheet 2 I I a; INVENTORS w. w. PABST' FAN cous'raucnou OF ACID RESISTANT PLASTIC MATERIAL Filed Nov. 24. 1953 4; Sheets-Sheet 3 HIII IIIIII lLllll 5 Wm m m M A d m S QQN QN QQ H g Jan. 3, 1961 w. w. PABST 2,967,014

FAN CONSTRUCTION OF ACID RESISTANT PLASTIC MATERIAL INVENTOR ATTORNEY United States Patent FAN CONSTRUCTION OF ACID RESISTANT PLASTIC MATERIAL Walter W. Pabst, Pabst Engineering Equipment Co. Inc, 676 Pennsylvania Ave., Elizabeth, N J.

Filed Nov. 24, 1953, Ser. No. 394,039

6 Claims. (Cl. 230134) The present invention relates to a fan construction of acid resistant plastic material, and it particularly relates to a fan construction which may be used for circulating corrosive fumes or other corrosive vapors.

It is among the objects of the present invention to provide a fan construction of molded, extruded, shaped or cut plastic elements which may be readily assembled and which is capable of high duty performance without likelihood of breakdown even though highly corrosive fluids and vapors are handled thereby, and which is capable of long operation.

Another object is to provide a novel, all plastic, high speed air or gas fluid circulating fan which may be made entirely of plastic materials or which may be formed of plastic exposed parts and central concealed or protected metal parts, and which will be capable of handling a wide variety of gases at very high capacities over long periods of time without breakdown or excessive maintenance.

Still further objects and advantages will appear in the more detailed description set forth below, it being understood, however, that this more detailed description is given by way of illustration and explanation only and not by way of limitation, since various changes therein may be made by those skilled in the art without departing fro the scope and spirit of the present invention.

In accomplishing the above objects it has been found most satisfactory to provide a central plate or spider for carrying a plurality of plastic plates mounted thereon in radial fashion.

In the preferred form one single spider is utilized with the plates welded thereon so as to project on both sides of the spider and desirably slotted connections are employed.

In this connection the slotted connection is'so located that the direction of the rotation of the fan will force the .vanes on to and more closely to the slotted connections. In addition to the slotted connections the fan vanes are also welded in position.

In an alternative construction a plurality of spiders-are I 7 thermal, chemical and physical properties. a

This plastic has high dimensional stability inert from a chemical point of view and is not subject to breakage or breakdown even when subjected to physical shock or electrical discharge. I

This material may be compression or transfer molded and extruded, or the fan parts may be cut out of sheets, rods or tubes which may subsequently be formed, welded and connected.

The preferred resin or plastic, such as vinyl chloride,

has a specific gravity of 1.2 to 1.6 and the plastic shall retain its structural character at all temperatures below 200 F., and preferably below F. It is a tough, rigid material, translucent or opaque, depending upon the thickness of the section employed. These plastic materials are also known as Lucoflex or Boltaron.

The metal structure is desirably connected with the central mountings and shafts and these metal mountings are desirably covered by a plastic shell or housing so tha they will not be exposed to gas or acid fumes.

With the foregoing and other objects in view the invention consists of the novel construction, combination and arrangement of parts as hereinafter more specifically described, and illustrated in the accompanying drawings, wherein is shown an embodiment of the invention, but it is to be understood that changes, variations and modifications can be resorted to which fall within the scope of the claims hereunto appended.

In the drawings wherein like reference characters denote corresponding parts throughout the several views:

Fig. l is a front elevational view of one form of the fan construction according to the present invention taken upon the line 1-1 of Fig. 2.

Fig. 2 is a transverse side sectional view taken upon the line 2-2 of Fig. 1.

Fig. 3 is a front elevational view of the spider without the vanes mounted thereon.

Fig. 4 is a fragmentary transverse sectional view upon the line 44 of Fig. 3.

Fig. 5 is a plan view of one of the vanes before being mounted upon the spider of Fig. 3.

Fig. 6 is a transverse sectional view upon the line 6-6 of Fig. 5.

Fig. 7 is a side sectional view of an alternative fan construction with a triple spider instead of the single spider of Fig. 1 taken upon the line 77 of Fig. 8.

Fig. 8 is a transverse sectional view upon the line 88 of Fig. 7 showing the vane construction.

Fig. 9 is a fragmentary transverse sectional view upon the line 99 of Fig. 7.

Fig. 10 is a plan view of one of the vanes as shown in Fig. 9 removed from the spider.

Fig. 11 is a transverse longitudinal sectional view of the fan construction of Figs. 1 and 2 in a modified type of easing, showing the drive and flow connections and taken upon the line 1111 of Fig. 12.

Fig. 12 is an end elevation view of the fan casing and supporting structure, together with the drive motor, taken from the line 1212 of Fig. 11.

7 Referring to Figs. 1 to 6 there is shown a fan B provided with a housing A having a central drive shaft C. The fan is essentially composed of the spider D and the vanes E, which are of trapezoidal or irregular polygonal shape.

The drive connection is enclosed by the housing F. The

vanes E are best shown by themselves in Figs. 5 and 6 and the spider D is best shown by itself in Figs. 3 and 4. Referring particularly to Figs. 3 and 4 the spider, which may be formed from a sheet of unplasticized polyvinyl chloride, has a central hub portion 10 with a shaft receiving a central opening 11 and hub bolt openings 12. The shaft and bolt connections extending through the openings ,10 and 11 may be suitably covered so as to protect them from fumes.

The hub has the outwardly extending arms 13 forming the spider, six arms being shown. A larger or smaller number of arms may be employed.

It will be noted that the arms taper having a wide base end 14 and a narrow end 15 at the periphery.

'The' direction of rotation as indicated by the curved arrow 16 and the edge of the vanes 13 opposite the di- '3 rection of rotation are beveled as indicated at'17. 'This double bevel 17 reduces the .noise and gives streamlining and permits more quiet operation.

The forward edge 18 of the arms 13 are provided with the outstanding lugs '19 for connection to the transverse vanes which are mounted thereon.

The vanes themselves are best shown in'Fig. and they are of irregular pentagonal or trapezoidal form with a central wedge 20 and the perip'heral'broad portion 21.

The central portion of the vanes is provided with the rectangular recesses or opening 22 to be received on the lugs 19 and the sides of the recess are beveled as indicated at 23 on .one side to permit a welded connection to be made which will hold the vanes permanently in position on the lug 19 and on the arms '13.

It will be noted that the vanes are shaped so that they have the inclined or pointed triangular edges 24 and 25 which may conform to the shape of the casing A, and the straight outside edge 26 is beveled off as indicated at 27. The inside central bevel 28 enables better fitting in respect to the hub portion of the spider D. The triangular edge has its trailing edges'bevelled as indicated at 24a and 25a in Fig. 2.

The assembled vanes and spider are best shown in Figs. 1 and 2. I

As shown in Figs. 1 and 2 there is a steel shaft 40 which is covered by a plastic sleeve 41. The shaft carries the steel plates 42 and 43 which are bolted together by means of the steel bolts 44. These bolts will clamp together the resinous plate 45, the central hub portion 10 of the spider D, and the resin plate 46.

The plate 42 may be welded to the end of the shaft 40. The plate 42, the shaft 40 and the bolts 44 are protected at the front end of the fan by the dome member 46a which may be shaped out of a flat piece of resinous material and welded at its periphery 47 to the resinous plate connector 45. This will .form the front enclosure to protect the metal elements from the fumes.

Welded to the sleeve 41 may be the resinous plate 55 which has the welded connection at 56 to the interior 57 of the dished portion 58 of the hub plastic plate 46.

It will be noted that the inside edges 59 of the vanes E will conform to the shape and contour '60 of the dished portion 58 and may be welded or otherwise permanently mounted thereon.

By the arrangement shown the steel bolts 44, the steel shaft 40 and the metal plates 42 and 43 which clamp the resin plates 45 and 46 against the hub 10 are all protected and enclosed so that they will not be exposed to the acid fumes.

The housing is only diagrammatically shown and it has an inlet funnel 70 with the connection flanges 71. The funnel end has an inturned portion 72 which conforms to the edges 25 of the vanes E.

The front and back walls 73 and 74 of the housing are connected to an exterior casing of proper shape of involute or convolute form.

This exterior casing is held in position by means of the stepped portion 74 and 75 and the bolts 76 with the protective plastic heads 77. The reenforcement vanes or plates 78 are welded in position as indicated at 79 and 80 to reenforce the walls 72 and 73.

The welded connection between the lugs 19 and the vane openings 22 is indicated by the square double lined portions 81 (see Fig. 2). A number of these ribs 78 may be provided to give suitable reenforcement to the casing.

The applicant has thus provided a high speed, durable, substantially integral polyvinyl plastic fan construction in which the metal central connection parts, namely the shaft 40 and the bolts 44, are housed by plastic elements F.

In the alternative construction of Figs. 7 to 9 there is shown a central drive shaft arrangement M which has a housing N and the triple plate P, Q and R.

The vanes V are mounted between the two outside plates P and R and are supported by the intermediate plate Q.

The metal or steel shaft M is protected by the plastic sleeve 100. The end of the shaft 101 is Welded at 102 to the metal plate 103.

The bolts 104 extend through the plate 103andclamp in position the hub 105 of the plate P and also the'hub 106 of the plastic clamping plate 107.

The nut elements 103 are protected by the annular plastic plate 109 welded in position'110 and 111 and also by the inside plate 112 welded in position at 113 to the sleeve or collar 100.

At-the inside .face of the plate P is the cup 114, the inturned edges 115 which are welded in position as indicated at 116.

The vanes have .the shapes as shown in Fig. 10. The vanes as shown have the circulating portions .and 126 with the end lugs 127 and 128 and the intermediate slot 129.

The lugs 128 and 129 as shown in 'Fig. 9 are fitted into the recesses 130 and 131 which are arranged circularly around the plates P and R. These recesses or slots 130 and 131 have bevel cutouts 132 and 133 which permit welding of the lugs 127 and 128 in position to the plates P and R.

The slots 129 are designed to receive the intermediate reenforcement ring 134. The vanes are then welded in position as indicated by the shade welded fillets at 135, 136 137 and 138.

As a result there 'Will'be formed a very rigid and durable cage construction as shown best in Figs. 7, 8 and 9, in which the rotating parts will be placed in a housing similar to Figs. 1 and 2, and in which the metal parts 103, 104 and 108 will be kept in separate central enclosures formed 'by the cup 114 and by the plates 107, 109 and 112.

The connections of'thevanes V'to the outside plates P and R 'and the intermediate reenforcing plate Q will assure a rigid, durable construction which will stand up throughout operation.

It will be noted in both the embodiment of Figs. 1 and 2 and both the embodiment of Figs. 7 and 8 that the hub portions will be bolted firmly in position between the metal plates so as to distribute the load over the entire hub, and nevertheless this metal shaft and bolt and plate connections are all sealed from contact with the corrosive fluids being circulated.

All corners are desirably rounded and the blades are generally positioned olf center so as to prevent pulsating and pumping. It is also possible to avoid noise by suitable beveling of the trailing edges.

Referring to Figs. 11 and 12 the fan structure with the blades E and the central dome F-is mounted inside of the casing 200, which is of involute shape as best shown in side the elevation view of Fig. 12.

The casing is made up of two side wall members 201 and 202, which are far around the periphery of which is wound a fiat strip of resinous material 203, which is welded into position as indicated at 204, 205 and 206.

The wall 201 has an interior structural plate 207 for stiffening purposes, which is bolted at 209, 210 and 211 to the end wall 2120f the supporting standard or frame structure 213.

The frame structure 213 has a base plate 214 with the peripheral flange 215.

Mounted upon the base 214 are the legs 216 of the motor housing 217, which is bolted into position as indicated at 218.

The bottom 219 .of the involute .housing 200 also rests upon the floor 124 of the standard 213 as indicated at 220.

The drive shaft .225. of the motor .217 .hasja :drive pulley 226 which drives the belt 227.

The belt 227 drives the upper pulley 228 which in turn drives the main drive shaft 229.

The main drive shaft 229 has bearings 230 and 231 which are mounted upon the platform 232.

The shaft 229 has the bearing connection 230 which drives the fan structure E-F.

The wall 202 is provided with an opening 240 in which may be inserted the circular Well 241 of the outlet duct 242.

The annular peripheral oblique well structure 241 performs the same function as the Wall 72 in Fig. 2 and in closer conformance to the edge 25 of the fan vanes E.

This well has an exterior diameter which is smaller than the opening 240 so that it may be inserted into said opening.

To the well or month 241 is welded the conical section 243 at 245. Intermediate of this conical section there is provided the attachment flange 246, which is bolted at 247 to the wall 202 adjacent to the periphery opening 240.

The gasket or seal 248 will make a tight connection between the flange 246 and the wall 202 of the fan housing 200.

The end of the section 243, as indicated at 248, is welded at 249 to the cylindrical section 250.

The cylindrical section 250 is provided with a plastic expansion joint 251, which is attached to another cylindrical section 252.

The duct section 253 and the expansion joint section 252 are connected together by the weld 254.

The vapors or gases will be drawn in as indicated by the arrow 255 and will be exhausted as indicated by the arrow 256 and in their passage through their housing 2%. They will not contact any metal parts but only the plastic fan structure E-F and the plastic housing 200. The bolts 209 to 211 and 247 and the interior plate 207 may be treated so as to be resistant to acid fumes or they may be enclosed by the plastic material.

As many changes could be made in the above fan construction of acid resistant plastic material, and many widely different embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

Having now particularly described and ascertained the nature of the invention, and in what manner the same is to be performed, what is claimed is:

1. In a fan for corrosive fluids having corrosive resistant plastic parts contacting the fluid and metal parts completely covered by and protected by said plastic parts, a rotary fan construction comprising a central plastic spider, said spider including outwardly extending narrow triangular arms with forward flat edges, the planes of which are parallel to the axis of rotation, a plurality of transverse plastic vanes mounted upon said spider and tongue and slot connections between said spider and said vanes, said vanes having trailing edges at one side thereof, each with a projecting triangular point, and having edges transverse to the rotation of the axis at the other side thereof and said slot connection being recessed around the tongue to receive a cement to fix the vanes in position against forward fiat edges of the outwardly extending narrow triangular arms.

2. The fan of claim 1, said spider having a plurality of radiating arms with tongues projecting from the edges thereof and said vanes having slots by which said vanes are mounted on said arms.

3. The fan of claim 2, said arms being of triangular shape and said vane being of irregular polygonal shape.

4. The fan of claim 1, said blades being positioned off center and the trailing edges being bevelled.

5. A fan construction of acid resistant polyvinyl chlo ride plastic material, comprising a flat plastic spider plate having outwardly projecting radiating trailing triangular flat arms integrally formed from said plate each having a forward projecting lug and each having a rearwardly tapered bevelled trailing edge, a central shaft having its end connected to the center of said spider plate, flat fan blades having recesses to be received on said lugs with the edges of the recesses being bevelled to permit of a welded joint connection between the blades and the arms, a plastic cup at one side mounted on the central part of the plate to cover the end of said shaft and a plastic circular outwardly extending dished member to cover the shaft on the other side of the spider plate, the edges of said blades first diverging outwardly from the center of the spider plate toward the recess and then converging beyond said recess and terminating in a straight edge transverse to the spider plate and parallel to the shaft, the inside edges of the blades contacting and conforming to the face of said dished member, the opposite forward edges of the blades being bevelled and an enclosing plastic housing having inlet and outlet conduits leading air to and from the rotating blades.

6. An all plastic fan construction comprising a fiat plate spider having a central mounting opening with radially outwardly extending arms with forward and rear edges converging together at the outer ends of the arms, the rear edges being bevelled and the forward edges being fiat-and having an intermediate rectangular attachment lug and fan blades having a narrow end and a wide end and having transverse and trailing edges and mounted against said flat forward edges and having a rectangular recess in the middle thereof with recessed countersunk edges, said recess fitting onto said lug and said countersunk edges receiving cement to hold said blades against said fiat forward edges, the narrow ends of said blades being at the widest part of said arms and the wide ends of said blades being at the narrow ends of said arms, the trailing edges of said blades being pointed and bevelled and the transverse edges of said blades being transverse the central axis of the spider.

References Cited in the file of this patent UNITED STATES PATENTS 1,381,673 Sherwood June 14, 1921 1,585,669 Hansen May 25, 1926 1,665,458 Hollander Apr. 10, 1928 1,877,347 McMurdie Sept. 13, 1932 1,895,488 Reisinger Jan. 31, 1933 2,557,201 Punt June 19, 1951 2,616,764 Parrish Nov. 4, 1952 2,626,741 Osborne Jan. 27, 1953 FOREIGN PATENTS 662,105 Great Britain Nov. 28, 1951 851,726 Germany Oct. 6, 1952 OTHER REFERENCES British Plastics Publication, The Moulding of Vinyl, Chloride Polymers," June, 1946. Pages 238-252.

Modern Plastics Publication, The Hard Vinyls, April, 1952. Pages 87-93. 

